261544133672 has 8 divisors (see below), whose sum is σ = 490395250650. Its totient is φ = 130772066832.

The previous prime is 261544133657. The next prime is 261544133677. The reversal of 261544133672 is 276331445162.

261544133672 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 257278215076 + 4265918596 = 507226^2 + 65314^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (261544133677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16346508347 + ... + 16346508362.

Almost surely, 2^261544133672 is an apocalyptic number.

It is an amenable number.

261544133672 is a deficient number, since it is larger than the sum of its proper divisors (228851116978).

261544133672 is a wasteful number, since it uses less digits than its factorization.

261544133672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32693016715 (or 32693016711 counting only the distinct ones).

The product of its digits is 725760, while the sum is 44.

The spelling of 261544133672 in words is "two hundred sixty-one billion, five hundred forty-four million, one hundred thirty-three thousand, six hundred seventy-two".